DESCRIPTION (Verbatim from the Applicant's Abstract): Laryngeal videoendoscopy combined with stroboscopy is now a mainstay for clinically assessing how the larynx functions to produce voice. Evaluation of the video imagery is currently limited to subjective visual judgments that can result in diminished reliability. A method enabling dimensional calibration of the images, and thus quantification of important vocal parameters, would greatly enhance the clinical and research capabilities of videoendoscopy with stroboscopy. Thus, the main goal of the proposed project is to investigate the feasibility of developing a laser-based projection system for dimensional calibration of laryngeal videoendoscopic images. The longer-term objective is to develop technology that is widely applicable to flexible endoscopy of the upper airway (including larynx). The near-term focus will be to develop an optical-based object sizing system for a flexible fiberoptic transnasal nasopharyngoscope. The Phase I tasks to be performed include: (1) developing a miniaturized design for a reference beam delivery channel compatible with the small caliber and flexibility required of a nasopharyngoscope, (2) specifying requirements for a reference beam laser illumination source compatible with videostroboscopic operation, (3) quantifying the object measurement accuracy achievable with such a system, and (4) developing a preliminary engineering design for a complete system suitable for clinical investigations. The Phase II effort would entail: (1) construction of a complete clinical prototype of the calibrated endoscope system, and (2) extensive clinical testing of the system at the Massachusetts Eye and Ear Infirmary (MEEI). PROPOSED COMMERCIAL APPLICATION: The market potential for a user-friendly calibration system customized for laryngeal video-stroboscopy is estimated to be several hundred units in the U.S. Similar systems for more general use flexible endoscopy of the upper airway (including larynx) have a potential worldwide market of up to several thousand units. The latter market reflects the large number of ototolaryngologists that use such scopes in routine clinical practice.